Myocardial scintigraphy with infarct-specific radiotracers

Among the hot-spot imaging agents, sup(99m)Tc stannous pyrophosphate (Tc-PyP) has been the most successful in clinical myocardial infarct imaging. To delineate the distribution of Tc-PyP accumulation and regional myocardial blood flow, the radioautographic method was adapted to study myocardial infarction produced experimentally in dogs. The experimental results suggest that acute infarct scintigraphy with Tc-PyP can be expected to have predictive value in assessing patients with acute myocardial infarction. Tc-PyP imaging was performed on 117 patients with sustained documented myocardial infarction. The results conclude that Tc-PyP scintigraphy is a sensitive and specific indicator of the presence of acute myocardial necrosis, if the limitations are borne in mind, especially in cases with myocardial contusion and myocardial infarction following cardiac surgery where ECG may not be specific and serum enzyme changes are inconclusive because of skeltal muscle trauma. (Auth.)